Generally, input-output (IO) circuitry may be utilized for conveying signals into and out of an integrated circuit (IC). As semiconductor technology advances, the size of the channel formed between the drain and the source of a transistor within IO circuitry shrinks. As the size of the channel becomes smaller, the maximum voltage that may be applied across the channel decreases. However, voltage requirements imposed by different IO standards have remained somewhat constant. Therefore, IO circuitry designs may have to be modified to satisfy the requirements of different IO standards.
To meet an IO standard, IO circuitry typically use stacked transistors to output a high voltage signal from the integrated circuit. However, transistors with shorter channel lengths may be more susceptible to hot carrier injection failures since transistors with shorter channel lengths may exhibit a lower threshold voltage compared to transistors with longer channels. A hot carrier injection phenomenon occurs when an electron in the transistor channel with sufficient energy (hence the term ‘hot’) enters the gate dielectric of the transistor.
The hot carrier injection phenomenon may be mitigated by utilizing high voltage transistors. However, utilizing high voltage transistors may require additional manufacturing process steps, resulting in increased cost. Therefore, utilizing high voltage transistors may be undesirable.
It is within this context that the embodiments described herein arise.